Effects of Age and Sex on Retinal Thickness in Non-Diseased Eyes Measured by Spectral-Domain Ocular Coherence Tomography: The Beaver Dam Eye Study

Abstract

Purpose: To determine the relationships of age and sex with retinal thickness in the macula measured by spectral-domain ocular coherence tomography (SD-OCT) in persons without clinical evidence of retinal disease.

Methods: Participants were aged 63-100 years at the 2008-2010 Beaver Dam Eye Study 20-year examination. SD-OCT images were obtained using the Topcon SD-OCT and were processed with Topcon 3D-OCT software. Reliability of the OCT segmentation was assessed. Retinal thickness from the top of the inner limiting membrane to the bottom of the retinal pigment epithelium was measured. Thickness measures from the center subfield, average of the four inner and average of the four outer subfields were analyzed. Presence of retinal diseases (e.g., age-related macular degeneration, diabetic retinopathy, epiretinal membranes, macular holes, edema and cysts) was determined by ophthalmoscopy, grading of fundus photographs and/or SD-OCT scans. Age was categorized as 63-74 years, 75-84 years and 85+ years.

Results: Of the 3032 eyes from 1544 individuals with SD-OCT scans, 1519 eyes from 748 individuals were free of retinal disease. The retina was thickest in the inner subfields (334 μm ± 16 μm) and thinnest in the center subfield (285 μm ± 22 μm). Mean retinal thickness decreased with age in the inner (reported as youngest vs. oldest age group, P value for trend per increasing age group; 337 μm vs. 326 μm, P<0.01) and outer (292 μm vs. 283 μm, P<0.01) but not center (285 μm vs. 279 μm, P=0.51) subfields. Adjusting for age, eyes in men had thicker retinas than eyes in women in the center (reported as men vs. women, P value; 291 μm vs. 280 μm, P<0.01), inner (336 μm vs. 332 μm, P<0.01) and outer (290 μm vs. 288 μm, P<0.01) subfields.

Conclusions: Our findings show that, in eyes without retinal disease, retinal thickness decreases with age in the inner and outer subfields and is thicker in men. These data provide population-based estimates of retinal thickness in eyes without clinical evidence of retinal disease. Reasons for the thinning of the retina with age and relationships to visual function and ocular and systemic disease remain to be determined.

Keywords: 413 aging • 463 clinical (human) or epidemiologic studies: prevalence/incidence • 688 retina